19
MAXIMUM ALLOWABLE PIPE LENGTH -- FT. (M) (CONTINUED)
ALTITUDE
FT. (M)
UNIT SIZE
(BTUH) DIRECT VENT (2-PIPE) ONLY
NON-DIRECT
VENT (1-PIPE)
ONLY
NUMBER OF 90°ELBOWS
TERMINATION
TYPE
PIPE DIA
IN. (mm)*
PIPE DIA
IN. (mm)* 1 2 3 4 5 6
7001 to 8000‡
(2134 to 2438)
40,000
2Pipeor2-in.
(51 mm)
Concentric
1-1/2 (38) 1-1/2 (38) 49
(14.9)
44
(13.4)
39
(11.9)
34
(10.4)
33
(10.1)
28
(6.5)
2 (51) 2 (51) 66
(20.1)
65
(19.8)
63
(19.2)
62
(18.9)
60
(18.3)
59
(18.0)
60,000
2Pipeor2-in.
(51 mm)
Concentric
1-1/2 (38) 1-1/2 (38) 12
(3.7)
7
(2.1) NA NA NA NA
2 (51) 2 (51) 53
(16.2)
48
(14.6)
46
(14.0)
41
(12.5)
40
(12.2)
38
(11.6)
80,000
2Pipeor2-in.
(51 mm)
Concentric
2 (51) 2 (51) 36
(11.0)
31
(9.4)
19
(5.8)
14
(4.3)
12
(3.7) NA
2-1/2 (64) 2-1/2 (64) 66
(20.1)
65
(19.8)
63
(19.2)
62
(18.9)
60
(18.3)
59
(18.0)
100,000
2Pipeor3-in.
(76 mm)
Concentric
2-1/2 (64) 2-1/2 (64) 25
(7.6)
17
(5.2)
8
(2.4)
7
(2.1) NA NA
3 (76) 3 (76) 63
(19.2)
58
(17.7)
53
(16.2)
48
(14.6)
43
(13.1)
38
(11.6)
120,000
2Pipeor3-in.
(76 mm)
Concentric
3 (76)† no disk NA 20
(6.1)
13
(4.0)
7
(2.1) NA NA NA
NA 3 (76)† 46
(14.0)
44
(13.4)
43
(13.1)
41
(12.5)
40
(12.2)
38
(11.6)
4 (102)† no
disk 4 (102)† no disk 61
(18.6)
56
(17.1)
51
(15.5)
46
(14.0)
41
(12.5)
36
(11.0)
140,000 NA
ALTITUDE
FT. (M)
UNIT SIZE
(BTUH) DIRECT VENT (2-PIPE) ONLY
NON-DIRECT
VENT (1-PIPE)
ONLY
NUMBER OF 90°ELBOWS
TERMINATION
TYPE
PIPE DIA
IN. (mm)*
PIPE DIA
IN. (mm)* 1 2 3 4 5 6
8001 to 9000‡
(2438 to 2743)
40,000
2Pipeor2-in.
(51 mm)
Concentric
1-1/2 (38) 1-1/2 (38) 46
(14.0)
41
(12.5)
36
(11.0)
31
(9.4)
29
(8.8)
24
(7.3)
2 (51) 2 (51) 62
(18.9)
60
(18.3)
58
(17.7)
56
(17.1)
55
(16.8)
53
(16.2)
60,000
2Pipeor2-in.
(51 mm)
Concentric
1-1/2 (38) 1-1/2 (38) 11
(3.4)
6
(1.8) NA NA NA NA
2 (51) 2 (51) 49
(14.9)
44
(13.4)
42
(12.8)
37
(11.3)
35
(10.7)
34
(10.4)
80,000
2Pipeor2-in.
(51 mm)
Concentric
2 (51) 2 (51) 33
(10.1)
28
(8.5)
17
(5.2)
12
(3.7)
10
(3.0) NA
2-1/2 (64) 2-1/2 (64) 62
(18.9)
60
(18.3)
58
(17.7)
56
(17.1)
55
(16.8)
53
(16.2)
100,000
2Pipeor3-in.
(76 mm)
Concentric
2-1/2 (64) 2-1/2 (64) 23
(7.0)
15
(4.6)
7
(2.1)
5
(1.5) NA NA
3 (76) 3 (76) 59
(18.0)
54
(16.5)
49
(14.9)
44
(13.4)
39
(11.9)
34
(10.4)
120,000
2Pipeor3-in.
(76 mm)
Concentric
3 (76)† no disk NA 10
(3.0) NA NA NA NA NA
NA 3 (76)† 43
(13.1)
41
(12.5)
39
(11.9)
37
(11.3)
35
(10.7)
34
(10.4)
4 (102)† no
disk 4† no disk 35
(10.7)
30
(9.1)
25
(7.6)
20
(6.1)
15
(4.6)
10
(3.0)
140,000 NA
See notes at end of table.
58MXB
